Pencil sharpener



July 29,1941# E. c. HOFFMANN 2,251,053

PENCIL SHARPENER Filed Deo. 28, 1959 5 sheets-sheet 1 Ill July 29, 1941. E. c. HOFFMANN l `PENmL SHARPENER Filed Dec. 28, 1939 0 lz Z7 lo? za n 34 3f y y uw" 6,8

July 29, 1941. E. c. HFFMANN 2,251,053v IENQIL SHARPENER f I Filed Dec. 2s, 1959 y j s sheetssheet s /A//FA/roe:

#fro-uwen Patented July 29, 1941 zeroes? v PENCIL SHARPENER Edward C. lllomann', University ('ity. Mo.. as-

signor to Triple E Products Co.. St. Louis. Mo., a corporation of Missouri Application December 28. 1939, Serial No.`3ll.26l

(Cl. F- 96) 6 Claims.

pencil Sharpener, the connections between the Sharpener and the motor of which are constructed to prevent stalling or jamming of the motor during the sharpening of a pencil.

Another object is to provide a power-driven pencil Sharpener having means to receive pencils of different diameters.

Another object is to provide a power-actuated pencil Sharpener in which the cutting mechanism is disposed at an angle to the horizontal of less than 90.

Another object is to provide a motor-operated pencil Sharpener having a high-speed small motor connected to the pencil-sharpening mechanism by indirect driving mechanism.

Another object is to provide a novel, compact, power-driven pencil Sharpener Sufliciently small t'o be used upon a desk or upon a wall.

Anotherobject is to provide a compact, poweroperated pencil Sharpener, small enough for use upon a desk or wall, yet powered sufciently to prevent stalling or jamming of the motor during sharpening of the pencil.

Another object is to provide a power-actuated pencil Sharpener which is ecient in operation land which is adapted to fulll all of the objects and advantages therefor.

Other objects and advantageswill be apparent from the following description, taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a front view of a mwen-actuated pencil Sharpener constructed in accordance with the teachings of the present invention;

Fig. 2 is a central sectional view through the housing of the pencil Sharpener shown in Fig. 1, the internal mechanism being shown in side elevation;

Fig. 3 is a section on the line 3 3 of Fig, 2;

Fig. 4 is a section on the line 4 4 of Fig. 1;

Fig. 5 is a Section on the line 5 5 of Fig. 4;

Fig. 6 is a section on the line 6 6 of Fig. 2;

Fig. 7 is a section on the line l-'l of Fig. 4;

Fig. 8 is a Section on the line 1 1 of Fig. 4, the mercury Switch being shown in contact relation;

Fig. 9 is a section on the line 9 9 of Fig'. 4;

Fig. 10 is a section on the line ID-l of Figs. 3 and 11;

Fig. 1l is a section on the line of Fig. 3, a pencil being shown in dotted lines with the point engaging the blunt-point stop;

Fig 12 is a section on the line Il l I of Fig. 3, a pencil being Shown in dotted linesl with the point against the fine-point stop;

Fig. 13 is a section on the line |3 |3 of Figs. 4 and 11;

Fig. 14 is a section on the line M-Id of Figs. 3 and 11;y

Fig. 15 is a section on the line |5 |5 of Figs. 3 and 11;

Fig. 16 is an enlarged side view of the cutting mechanism with the cutter cylinders removed;

Fig. 17 is an enlarged top view of elements of the cutter mechanism, showing a modified web; and,

Fig. 18 is a section on the line l8 |8 of Fig. l.

Referring to the'drawings more particularly by reference numerals, thereis disclosed a poweractuated pencil Sharpener generally designated 20. A base or support 2| (Figs. 2 and 4) supports beneath a cover or casing 22 a motor 24, a cutter mechanism 25, a connecting drive mechanism 26, a switch mechanism 21, and a shavings drawer 23.

The base 2| is preferably a casting comprising a horizontal portion 30, on the lower side of which is a. rubber mat 29, a vertical iin 3|, a wall 32 angularlydisposed relative to the fin 3| and extending forwardly therefrom, a wall 33 disposed at right angles to the wall 32 and extending rearwardly from the fin 3|, and a Wall 34 (Figs. 2 and 3) which is connected to the edges of the wall 32 and the wall 33. A casting 36 is secured to the walls 32 and 34 by Screws 3l, and includes a wall 38 parallel to the wall 33 and a wall 39 extending forwardly thereof of hood configuration. A plate 4|, preferably of the contiguration shown in Figs. 2-6, is secured to the free edge of the wall 39 by screws 42 and includes a flat portion 43 disposed in a plane parallel with the planes of the walls 33 and 36.

The cover 22 is Shown as of streamlined con-- figuration. The cover 22 is secured to the horizontal portion 30 of the base 2| by pins 45 (Fig. 1) which extend into recesses 46 formed in the A strip of felt, or the like (not shown), may be disposed between the exterior face of the wall 34 and the interior of the cover 22, if desired. The cover 22 includes a portion 49 which is in a plane parallel to the plane of the at portion 43 of the plate 4| when the latter is operatively connected to the casting 36. The portion 49 has an aperture 50 to receive a pencil. The cover 22 further includes an opening (Fig. l) in the front end` for the reception of the receptacle 28.

The motor 24 is secured by screws 52, or the like (Fig. 3), to the rear face of the wall 33. Power leads 53, 54, and 55 connect the motor 24 and the switch 21 in series, the leads 53 and 55 finding egress through the horizontal portion 3U of the base 2| (Fig. 2). The motor 24 includes a rotor shaft 51, one end of which extends through an aperture 58 in the wall 33.

The connecting drive mechanism 26 is disposed within a compartment formed by the wall 32, the `wall 33, the wall 34, and the wall 38. The mechanism 26 includes a pinion 60 fixed by any suitable means to the rotor shaft 51 of the motor 24. Meshing with the pinion 60 is a gear 6| which is fixed to a shaft 62 rotatably mounted in suitable bearings bosses 63 and 64 formed integrally with the walls 33 and 38, respectively. A pinion 65 is also fixed to the shaft 62 to rotate with the gear 6|. A gear 66 fixed to a reduced extremity 61 of a shaft 68 forming part of the cutter mechanism 25 meshes with the pinion 65.

The cutter mechanism 25 is disposed forwardly of the wall 38 within the hood-shaped wall 39. The details of the cutter mechanism are clearly shown in Figs. -17. An annular member 10 is fixed to the forward face of the wall 38 by screws 1|, or the like, and includes a central I aperture 12 disposed in alignment with an aperture 13 formed in the wall 38. The member 10 further includes an inwardly disposed annular shoulder 14 and a ring gear 15. A portion of the annular member 10 is cut away to provide a slot 16 for a purpose to be discussed infra (Figs. 4. l1, and 13). The member 10 may be formed as an integral part of the casting 36.

The afore-mentioned shaft 68 of the cutter mechanism is of the particular configuration shown in Figs. 11, 16, and 17. The shaft 68, in addition to the reduced extremity 61, includes a bearing segment 18 contiguous to the reduced extremity 61 and a bearing segment 19 at the opposite extremity thereof. The shaft 68 is formed to receive between the bearing segments 18 and 19 a pair of oppositely disposed cutter cylinders 80, each having affixed thereto at one end a gear-pinion 8|. The cutters 80 and pinions 8| are rotatably mounted in the shaft 68 for free rotary movement relative thereto. The shaft 68 is, in effect, cut away to receive the cutter cylinders 80, leaving opposed webs 82 and 83. The web 82 is cut away at 84, through which extends an apron 85. The web 83 is cut away at 86, through which extends an apron 81. The aprons 85 and 81 are angularly disposed and converge at the axis of rotation of the shaft 68 to form a finepoint stop 88. An annular shoulder 90 is lormed :1t the juncture of the bearing segment'18 with the central portion of the shaft 68.

The bearing,T section 18 of the shaft 68 hasbearing support in the aperture 12 of the annular member 10 with the annular shoulder 90 of the shaft 68 against the annular seat 14 of the annular member 1 0. The bearing segment 19 of the shaft 68 has bearing support in an aperture 9| formed in the portion 43 of the plate 4|. The pinions 8| are in operative engagement with the ring gear 15.

A blunt-point stop 92 is mounted on the web 82 and includes a link 93 pivoted to a support 94 forming part of or secured to the web 82, and a link 95 pivotally connected to the link 93. The link 95 extends through a suitable opening in the web 82 into the shaft 68. The bluntpoint stop 92 is shown in Fig. 11 in operative disposition and in Fi'g. 12 in inoperative disposition.

A switch mechanism 21 is mounted on the hood-wall 39 (Figs. 4-8). A shaft 98 includes a first portion 99 journaled in a bearing |00 acljustably fixed by screws |0|, or the like, to the outer face of the hood-wall 39, the bearing |00 including flanges |02 having slots |03 (Fig. 6) which receive the screws |0|. The shaft 98 includes an intermediate portion |04 angularly disposed relative to the portion 99, and a third portion |05 which .includes a fiat face |06 angularly disposed relative to the plane of the portion 43 of the plate 4|. A flat link |08 s fixed to the free end of the portion 99 of the shaft 98 by a nut |09, the link |08 bearing against a. suitable shoulder formed near the end of the 4portion 99. A mercury switch ||0 including a.

casing having spaced wires ||2 and a ball of mercury ||3 therein is xed to the other end o'f the link |08 by a clamp ||4 which engages the'casing and which is secured to the link |08 by a nut ||5. The switch mechanism 21 normally maintains the position shown in full linesin Fig. 5 through a stop |01 fixed to the shaft 98, but to close the circuit is easily rotatable to the position shown in the same figure in dotted lines. The leads 54 and 55 are connected to the spaced wires I|2.

Pivotally mounted on thev portion 43 of the plate 4| below the aperture 9| is a size-plate ||8 (Figs. 2-6 and 9). The plate ||8 is xed by welding or otherwise to a shaft ||9 which has one reduced extremity |20 bearing in the portion 43 and a reduced portion |2| bearing in the portion 49 of the cover 22. A knob dial |22 is removably connected to a second reduced extremity |23 of the shaft ||9 by a spring |24, or the like. The knob dial |22 has a pointer |25 (Fig. 1) which cooperates with indications l |26 on the outer face of the portion 49 of the cover 22 to show the positions of size apertures |21 (Fig. 5) relative to the aperture 19. The plate ||8 is disposed adjacent the outer face of the portion 43 of the plate 4|.

In Fig. 17, webs 82 and 83 4flare towards the end at which the aprons 85 and l'91 are formed.

rC)therwise, the elements are the same as deobtained.A

scribed. The flared construction assists in the direction'of shaved material.

Operation R. e. M. to 50o R, P. M. may,

Before sharpening a pencil, the size-plate ||8 is adjusted by means oi the knob indicator |22 to place the correct size opening in alignment with the aperture 19. The blunt-point stop 92 is adjusted to operative or inoperative position.

Normally, the size-plate ||8 will be disposed to' receive a standard size pencil and the blunt-point stop 82 will be in inoperative position.

A pencil is thrust through the aperture 50. The point ol the pencil contacts the face I86of the shaft 98 and deilects the same to the right (Fig. '5), thereby rotating the switch mechanism 21 counterclockwise to move the casing ||8 from the position shown in Fig. 7. to the position shown in Fig. 8, closing the motor circuit. The closing of the motor circuit and the starting thereby of the motor 24 and therefrom the cutter mechanism 25 through the drive mechanism 26 is substantially instantaneous so that the cutter cylinders 88 are in movement before the pencil comes into engagement therewith. The cutter cylinders 80 shave the graphite and encasing wood of the pencil until the point thereof contacts the fine-point stop 88, whereupon the cutter cylinders 88, although continuing to rotate, cease to actively point the pencil. This cessation of active shaving effect of the cutter cylin-l ders 88 is immediately perceptible to the individual sharpening the pencil, so that the sharpened pencil can be withdrawn without loss of time.

to dispose the casing in the position shown in Fig. 8, which is the closed circuit position.

posed at substantially 45 to approximate the angle at which a pencil is normally held in writing, The angular disposition of the barrel, de-

- fined, of course, by the position of the cutter The mechanical functioning of the pencil v Sharpener 20 is clear from the foregoing, taken in conjunction with the drawings. The motor 24 is of the high-speed type, a preferred motor running at 17,000 R. P. M. and adapted to function with either direct or alternate current. The drive mechanism 26 disposed between the motor 24 and the cutter mechanism 25 is an indirect drive, the advantages of which prevent stalling of the motor in sharpening a pencil. In a preferred embodiment, the high speed of the motor 24 is reduced by the connecting mechanism 26 to an effective speed of 500 R. P. M. as applied to the cutter mechanism 25. This ratio of 17,000 of course, be varied by using different gear ratios./ The point is that it is impractical to use a direct ldrive for motoractuated pencil sharpenersffor either the motor must be too large for a/practical pencil sharpener, or the device will stall unless handled in the most careful manner, something not to be eX- pected from a casual user.

The shaft 68 of the cutter mechanism 25 rotates, as has been stated, substantially 500 R. P. M. The cutter cylinders 88 rotate with the shaft 68, but they also rotate independently about their own axes through the contact of the pinions 8| with the ring gear 15. The aprons 85 and 81 shunt substantially all of the shavings and other material over the ring gear 15 and pinions 8| into the space below the cutter mechanism 68. However, the groove 16 permits any shavings and other` matcrial, which may work into the ring gear track to fall into the space below the cutter mechanism 25, and thence into the drawer 28.

The switch mechanism 21 is very effective in the automatic actuation of the motor 24. It is of light construction and of free pivotal movement. It is balanced, so that the casing normally assumes the position shown in Fig. 7. It requires but the. slightest force on the part of a pencil insertedthrough the opening 58 against the face |06 topivot the switch mechanism 21 shaft 58, permits one sharpening a pencil to insert it with facility. In other words, the present Sharpener 28 simplies to a minimum the sharpening approach in anticipating the normal A.

manner in which a pencil is held by one proceeding to sharpen the same.

Manifestly, there are possible changes in the construction and arrangement which are within the confines of the present inventive concept. The motor 24 may be of any suitable high-speed type. The gearing 26 may be varied as to ratio to reduce the effective speed of the motor 24 as desired for a particular Sharpener construction. The switch mechanism 21 may be of the contact typefaffconstruction `which would be preferable where the Sharpener was subjected to a considerable amount of movement, as upon a train or ocean liner, for it is possible' that upon these carriers the inevitable agitation transmitted to the sharpenerhwould occasionally close the motor circuit through 4an abrupt movement of the mercury ||3 into momentary contact with the wires H2. Manifestly, suitable materials and suitable configurations are to be employed for the elements of the Sharpener 28. v

It is apparent, therefore, that there has been provided a power-actuated pencil Sharpener which fulfills all of the objects and advantages sought therefor.

It is to be understood that the foregoing description and accompanying drawings have been given by way of illustration and example, and not for purposes of limitation, the invention being limited only by the claims which follow.

What is claimed is:

1. A pencil Sharpener comprising a casing, rotary cutting means mounted on said support, afnd means `for driving said cutting. means, said rotary cutting means including spaced cutting rollers, each having an associated pinion, a ring gear with which said pinions cooperate, and a pair of aprons overhanging the ring gear formed as part of the cutter shaft disposed to prevent the passage of shavings and other material from the cutters to the ring track.

2. A pencil Sharpener comprising la support, a casing, rotary cutting means mounted on said support, yand means for driving said cutting means, said rotary cutting means including spaced cutting rollers, each having an associated pinion, a ring gear with which said pinions cooperate, means for substaytially preventing the passage of shavings and o her material into the 3. A pencil Sharpener comprising a support, a

casing, rotary cuttingr means mounted on said support, and means for driving said cutting means, said rotary cutting means including spaced cutting rollers, each having an associated support, a

pinion, a ring gear with which said pinions cooperate, a pair of aprons formed as part of the cutter shaft disposed to prevent the passage of shavlngs and other material from the cutters to the ring track, and a groove in the member of which the ring gear forms a part leading from the lower part of the ring track into the space below the cutters to drop material which has sifted into the ring track.

4. A pencil Sharpener comprising a support, rotary cutting means mounted on said support, and means for driving said cutting means, said rotary cutting means including pinions by which said driving means rotates said rotary cutting means, a ring gear with which said pinions cooperate, and a pair of aprons overhanging the ring gear disposed to prevent the passage of shavings and other materials from the cutting means to the ring track.

5. A pencil Sharpener comprising a support,

rotary cutting means mounted on said support, and means for driving said cutting means, said rotary cutting means including spaced cutting rollers, each having an associated pinion, a ring gear with which said pinions cooperate, and means for discharging any shavings or other material from the ring track which may sift thereinto.

6. A pencil Sharpener comprising a support, rotary cutting means mounted on said support, and means for driving said cutting means, said rotary cutting means including spaced cutting rollers, each having an associated pinion, a ring gear with which said pinions cooperate, and a groove in the 4member of which the ring gear forms a part leading from the lower part of the ring track into the space below the cutters to drop material which has sifted into the ring track.

EDWARD C. HOFFMANN. 

